Transform Media

This is the core Openinary endpoint. The first request processes and caches the result; subsequent requests are served from cache in ~50ms.

Endpoint

GET /t/{transformations}/{path}

Auth: Public (rate limited)

Path parameters

transformations

string

Comma-separated transformation parameters. Omit this segment (or use t/) to serve the original file without transformations.w_800,h_600,c_fill,q_85,f_webp

path

string

required

Path to the file relative to the storage root, including the file extension.image.jpg · photos/portrait.png · videos/clip.mp4

Image parameters

Quick reference

Param	Full name	Description
`w`	width	Width in pixels
`h`	height	Height in pixels
`c`	crop	Crop/resize mode
`ar`	aspect ratio	Crop to a given ratio (`W:H`)
`a`	angle	Rotation angle or `auto`
`g`	gravity	Focal point for cropping
`b`	background	Background color (hex)
`r`	round corners	Radius in pixels, per-corner list, or `max`
`q`	quality	Compression level (1–100)
`f`	format	Output format

Parameter reference

integer

Width of the output image in pixels.w_800 · w_1920 · w_400

integer

Height of the output image in pixels.h_600 · h_1080 · h_400

string

default:"fill"

How the image is resized and cropped.

Value	Behavior
`fill`	Fill the area, cropping the overflow (default)
`fit`	Fit within dimensions, preserving aspect ratio
`scale`	Stretch to exact dimensions (distorts if ratios differ)
`crop`	Resize and crop to exact dimensions
`pad`	Fit and add background-colored borders

string

Crop the image to a specific aspect ratio. Format: W:H.ar_16:9 · ar_1:1 · ar_4:3

string | number

Rotate the image. Use auto to rotate based on data, or a number (0–360) for a fixed angle.a_auto · a_90 · a_180

string

default:"center"

Focal point used when cropping.

Value	Behavior
`center`	Center of the image (default)
`north`	Top edge
`south`	Bottom edge
`east`	Right edge
`west`	Left edge
`face`	Face detection, keeps the detected face in frame
`auto`	Entropy-based region of interest detection

string

Background color for c_pad (padding fill), a_<angle> (rotation fill), and r_<radius> (corner fill). Use rgb: followed by a 6-digit hex value.b_rgb:ffffff (white) · b_rgb:000000 (black) · b_rgb:f5f5f5 (light gray)

string

Rounds the corners of the image using an SVG alpha mask.

Syntax	Behavior
`r_<int>`	Same radius on all four corners
`r_v1:v2`	`v1` = top-left & bottom-right, `v2` = top-right & bottom-left
`r_v1:v2:v3`	`v1` = top-left, `v2` = top-right & bottom-left, `v3` = bottom-right
`r_v1:v2:v3:v4`	Each corner individually: TL, TR, BR, BL (clockwise)
`r_max`	Circle (square image) or oval (rectangular image)

r_80 · r_20:80 · r_20:0:40:60 · r_maxBy default, cut corners are transparent, use f_png, f_webp, or f_avif. Add b_rgb:<hex> to fill corners with a solid color and use any format including JPEG.

Radius is clamped to half the shorter dimension. Round corners are not supported for video.

integer

default:"85"

Compression quality from 1 (smallest file) to 100 (highest quality).

Range	Trade-off
90–100	High quality, larger file
80–89	Recommended sweet spot
60–79	Smaller file, slight quality loss
1–59	Aggressive compression, visible artifacts

string

Force a specific output format. When omitted, the best format is chosen automatically based on the browser’s Accept header.

Value	Notes
`avif`	Best compression (up to 50% vs JPEG)
`webp`	Excellent compatibility, ~30% vs JPEG
`jpeg` / `jpg`	Universal fallback
`png`	Lossless, supports transparency

Image examples

Resize
Smart crop
Aspect ratio
Format

GET /t/w_800,h_600/image.jpg

GET /t/w_400,h_400,c_fill,g_face/portrait.jpg

Square thumbnail cropped around the detected face.

GET /t/ar_16:9,w_1920/banner.jpg

GET /t/w_1200,f_avif,q_80/photo.jpg

Instagram portrait

GET /t/ar_1:1,w_1080,g_face,q_85,f_webp/portrait.jpg

Padded thumbnail

GET /t/w_400,h_300,c_pad,b_rgb:f5f5f5,q_80/thumbnail.jpg

Consistent dimensions with a light gray background on the borders.

Rotated PNG (with transparency)

GET /t/a_15,w_200,h_200/logo.png

Full HD AVIF

GET /t/w_1920,h_1080,q_85,f_avif/landscape.jpg

Circular avatar

GET /t/w_400,h_400,c_fill,r_max,f_png/avatar.jpg

Square crop then circular mask. Use f_png or f_webp to preserve the alpha channel, or add b_rgb:<hex> to fill corners with a solid color.

Rounded card image

GET /t/w_600,h_400,c_fill,r_16,b_rgb:ffffff/photo.jpg

Uniform 16 px radius with white corners, safe to serve as JPEG on a white page.

Supported image formats

Input: JPEG, PNG, WebP, AVIF, GIF (first frame), HEIC/HEIF (converted to JPEG on upload), PSD (layers composited) Output: AVIF, WebP, JPEG, PNG

Video parameters

Video processing is resource-intensive (5–30s per file). For high-traffic assets, prewarm transformed variants at upload time so the first request is served from cache.

Quick reference

Param	Full name	Description
`w`	width	Width in pixels
`h`	height	Height in pixels
`c`	crop	Crop/resize mode
`q`	quality	CRF quality (1–100)
`so`	start offset	Start time in seconds
`eo`	end offset	End time in seconds (trim)
`f`	format	Output format
`t`	thumbnail	Extract a single frame as an image instead of transcoding video
`tt`	thumbnail time	Time (seconds) to extract the thumbnail frame from

Parameter reference

integer

Width of the output video in pixels.w_1920 (1080p) · w_1280 (720p) · w_640 (SD)

integer

Height of the output video in pixels.h_1080 · h_720 · h_480 · h_360

string

default:"fill"

Resize/crop strategy. Requires w/h.

Value	Behavior
`fill` / `crop`	Scale and crop to fill the target dimensions, no stretching
`fit`	Fit within the dimensions, preserving aspect ratio
`scale`	Resize to exact dimensions, may stretch
`pad`	Fit within the dimensions and pad with background

boolean

default:"false"

Extracts a single frame as an image thumbnail instead of transcoding the video. When enabled, the output is an image format (jpg, png, webp, etc., set via f) rather than a video.t_true

number

default:"0"

Time in seconds to extract the thumbnail frame from. Only applies when t is enabled.tt_5.5 · alias: thumbnail_time

integer

default:"75"

Video quality via encoding. Range: 1–100.

`q` value	CRF	Notes
100	18	Very high quality
85	23	High quality, recommended
75	28	Balanced (default)
50	35	Smaller file, noticeable loss
10	45	Low quality, minimum size

number

Start time in seconds. Used for trimming (with eo) or thumbnail extraction (with an image f).so_5 · so_10.5

number

End time in seconds. Must be used together with so. The output duration is eo − so.so_5,eo_12 → 7-second clip

The end offset is exclusive: so_5,eo_12 produces a clip from 5s to 12s (7 seconds).

string

Output format. Defaults to mp4 (H.264). When combined with so and without eo, extracts a single frame as an image.

Value	Use case
`mp4`	Re-encoded video (H.264), default
`webp`	Frame thumbnail
`jpeg` / `jpg`	Frame thumbnail
`png`	Frame thumbnail with transparency

Video examples

720p HD
Trim
Thumbnail
Mobile preview

GET /t/w_1280,h_720,q_80/video.mp4

GET /t/so_5,eo_12/video.mp4

7-second clip (5s → 12s).

GET /t/w_400,h_300,so_5,f_webp/video.mp4

Single frame at 5s, output as a WebP image.

GET /t/w_640,h_360,q_60/video.mp4

Low-bandwidth version for mobile.

Trim and resize

GET /t/w_400,h_300,so_5,eo_12/video.mp4

7-second clip (5s → 12s) resized to 400×300.

High-quality presentation

GET /t/w_1920,h_1080,q_95/presentation.mp4

Supported video formats

Input: MP4 (H.264/H.265), MOV, WebM (VP8/VP9) Output: MP4 (H.264), standardized for maximum device and browser compatibility

Response

Returns the binary content of the transformed file.

Header	Value
`Content-Type`	Detected from output format (e.g. `image/webp`, `video/mp4`)
`Cache-Control`	Set for browser caching

Status codes: 200 success · 404 file not found · 500 processing error

Authenticated Transform

Signed URLs for restricted transformations.

Upload Files

Upload files and pre-generate variants.

Intelligent Compression

How Openinary picks the optimal format automatically.

Overview

Media

Files

Storage

Cache

Video Processing

API Keys

System

Endpoint

Path parameters

Image parameters

Quick reference

Parameter reference

Image examples

Supported image formats

Video parameters

Quick reference

Parameter reference

Video examples

Supported video formats

Response

Authenticated Transform

Upload Files

Intelligent Compression

​Endpoint

​Path parameters

​Image parameters

​Quick reference

​Parameter reference

​Image examples

​Supported image formats

​Video parameters

​Quick reference

​Parameter reference

​Video examples

​Supported video formats

​Response

​Related

Authenticated Transform

Upload Files

Intelligent Compression

Endpoint

Path parameters

Image parameters

Quick reference

Parameter reference

Image examples

Supported image formats

Video parameters

Quick reference

Parameter reference

Video examples

Supported video formats

Response

Related